was a of the Imperial Japanese Navy

Imperial Japanese Navy

The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

 built during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. Named after Mount Katsuragi, and completed late in the war; she never embarked her complement of aircraft and did not participate in any battles. The ship was badly damaged in a July 1945 airstrike by American carrier aircraft on Kure Naval Base. Repaired after the end of the war, Katsuragi was then used as a repatriation transport for a number of months, bringing Japanese soldiers and civilians back to Japan from overseas locations. She was scrapped

Ship breaking

Ship breaking or ship demolition is a type of ship disposal involving the breaking up of ships for scrap recycling. Most ships have a lifespan of a few decades before there is so much wear that refitting and repair becomes uneconomical. Ship breaking allows materials from the ship, especially...

 in Japan beginning in late 1946.

Design and description

The ultimate expression of Japanese carrier construction during World War II was a group of vessels based on an improved design, but with individual units differing in detail reflecting the changing circumstances as the conflict in the Pacific approached its conclusion. Katsuragi was ordered 25 June 1942, under the provisional name of #5003, as part of the Kai-Maru 5 Program

Modified 5th Naval Armaments Supplement Programme (Japan, 1942)

The was one of the wartime armaments expansion plans of the Imperial Japanese Navy .-Background:In September 1942, after being defeated in the Battle of Midway, the IJN drew up a new armaments expansion plan. This plan was combined by the 5th Naval Armaments Supplement Programme and the 6th Naval...

 of 1942. This was a massive naval construction program intended to replace losses suffered at the Battle of Midway

Battle of Midway

The Battle of Midway is widely regarded as the most important naval battle of the Pacific Campaign of World War II. Between 4 and 7 June 1942, approximately one month after the Battle of the Coral Sea and six months after Japan's attack on Pearl Harbor, the United States Navy decisively defeated...

 and focused on aircraft and aircraft carriers. The ship was one of 16 s planned, although only three were completed before the end of the war.
Katsuragi had a length of 227.35 metre overall. She had a beam

Beam (nautical)

The beam of a ship is its width at the widest point. Generally speaking, the wider the beam of a ship , the more initial stability it has, at expense of reserve stability in the event of a capsize, where more energy is required to right the vessel from its inverted position...

 of 22 metre and, at deep load, a draft of 7.93 metre. She displaced

Displacement (ship)

A ship's displacement is its weight at any given time, generally expressed in metric tons or long tons. The term is often used to mean the ship's weight when it is loaded to its maximum capacity. A number of synonymous terms exist for this maximum weight, such as loaded displacement, full load...

 22535 tonnes (22,179 LT) at deep load. Her crew consisted of 1,576 officers and men. When acting as a flagship

Flagship

A flagship is a vessel used by the commanding officer of a group of naval ships, reflecting the custom of its commander, characteristically a flag officer, flying a distinguishing flag...

 she had a total of 1,600 crewmembers.

A shortage of turbines and boilers led to machinery of the same type as that used in the being used in Katsuragi. These consisted of four geared steam turbine

Steam turbine

A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....

 sets with a total of 104000 shp driving four shafts, each fitted with a 3.75 metres (12.3 ft) propeller. Steam was provided by eight Kampon Type B water-tube boiler

Water-tube boiler

A water tube boiler is a type of boiler in which water circulates in tubes heated externally by the fire. Fuel is burned inside the furnace, creating hot gas which heats water in the steam-generating tubes...

s with a working pressure of 30 kg/cm2 at 350 °C (662 °F). The ship had a designed speed of 32 knots (17.4 m/s), but during sea trial

Sea trial

A sea trial is the testing phase of a watercraft . It is also referred to as a "shakedown cruise" by many naval personnel. It is usually the last phase of construction and takes place on open water, and can last from a few hours to many days.Sea trials are conducted to measure a vessel’s...

s on 12 October 1944, she reached 32.71 knots (17.8 m/s) at the light displacement of 18144 long tons (18,435.2 t). Katsuragi carried carried 3671 tonnes (3,613 LT) of fuel oil

Fuel oil

Fuel oil is a fraction obtained from petroleum distillation, either as a distillate or a residue. Broadly speaking, fuel oil is any liquid petroleum product that is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power, except oils having a flash...

 although no data on her range is known. She had two funnel

Funnel (ship)

A funnel is the smokestack or chimney on a ship used to expel boiler steam and smoke or engine exhaust. They can also be known in as stacks.-Purpose:...

s on the starboard side, each angled below horizontal. They were fitted with a water-cooling system to reduce the turbulence caused by hot exhaust gases.

Flight deck arrangements

Katsuragis flight deck

Flight deck

The flight deck of an aircraft carrier is the surface from which its aircraft take off and land, essentially a miniature airfield at sea. On smaller naval ships which do not have aviation as a primary mission, the landing area for helicopters and other VTOL aircraft is also referred to as the...

 was 216.9 metre long and had a maximum width of 27 metre. A small island was mounted well forward on the starboard side and contained the ship's bridge and air operations control center. It was fitted with a small tripod mast that mounted one of the ship's radar

Radar

Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

 antennaa

Antenna (radio)

An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...

s. The ship was designed with two superimposed hangar

Hangar

A hangar is a closed structure to hold aircraft or spacecraft in protective storage. Most hangars are built of metal, but other materials such as wood and concrete are also sometimes used...

s that were served by two aircraft elevators, each 14 by; the center elevator as used in Hiryū was deleted to simplify construction and reduce stress in the hull. The elevators had a maximum capacity of 7000 kilograms (15,432.4 lb) and took 19 seconds to go from the lower hangar to the flight deck. Katsuragi was fitted with hydraulically operated Type 3 arresting gear with nine cables. She also mounted three Type 3 crash barricades. No aircraft catapult

Aircraft catapult

An aircraft catapult is a device used to launch aircraft from ships—in particular aircraft carriers—as a form of assisted take off. It consists of a track built into the flight deck, below which is a large piston or shuttle that is attached through the track to the nose gear of the aircraft, or in...

 was fitted. The ship mounted a retractable crane

Crane (machine)

A crane is a type of machine, generally equipped with a hoist, wire ropes or chains, and sheaves, that can be used both to lift and lower materials and to move them horizontally. It uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of...

 on the starboard side of the flight deck, just aft of the rear elevator.

The ship's air group was originally intended to consist of 12 Mitsubishi A6M Zero fighters, plus three in storage, 27 Aichi D3A

Aichi D3A

The , Allied reporting name "Val") was a World War II carrier-borne dive bomber of the Imperial Japanese Navy . It was the primary dive bomber in the Imperial Japanese Navy, and participated in almost all actions, including Pearl Harbor....

 Val dive bombers, plus three in reserve, and 18 Nakajima B5N

Nakajima B5N

|-See also:-References:NotesBibliography* Bridgwater, H.C. and Peter Scott. Combat Colours Number 4: Pearl Harbor and Beyond, December 1941 to May 1942. Luton, Bedfordshire, UK: Guideline Publications, 2001. ISBN 0-9539040-6-7....

 "Kate" torpedo bomber

Torpedo bomber

A torpedo bomber is a bomber aircraft designed primarily to attack ships with aerial torpedoes which could also carry out conventional bombings. Torpedo bombers existed almost exclusively prior to and during World War II when they were an important element in many famous battles, notably the...

s (plus two in crates). Katsuragis hangars could not accommodate so many aircraft so eleven planes were planned to be permanently carried of the flight deck. In 1943 the air group was revised to consist of 18 Mitsubishi A7M

Mitsubishi A7M

|-See also:-References:NotesBibliography* Francillon, Ph.D., René J. Japanese Aircraft of the Pacific War. London: Putnam & Company Ltd., 1970 . ISBN 0-370-30251-6....

 "Sam" fighters (+2 in storage), 27 Yokosuka D4Y

Yokosuka D4Y

The D4Y Navy Type 2 Carrier Dive bomber was operated by the Imperial Japanese Navy. Its Allied reporting name was "Judy". The D4Y was one of the fastest dive-bombers of the war, and only the delays in its development hindered its service, while its predecessor, the slower fixed gear Aichi D3A...

 "Judy" dive bombers and six Nakajima C6N

Nakajima C6N

-See also:-References:NotesBibliography* Francillon, Ph.D., René J. Japanese Aircraft of the Pacific War. London: Putnam & Company Ltd., 1970. ISBN 0-370-00033-1 ....

 "Myrt" reconnaissance aircraft

Reconnaissance aircraft

A reconnaissance aircraft is a manned military aircraft designed, or adapted, to carry out aerial reconnaissance.-History:The majority of World War I aircraft were reconnaissance designs...

. Of these, the C6Ns were intended to be carried on the flight deck. When the ship commissioned in 1944, neither the A7M nor the C6Ns were yet in service, so the air group was reconfigured to consist of 27 Zeros, 12 D4Ys, three of which were to be the reconnaissance version, and nine Nakajima B6N

Nakajima B6N

The Nakajima B6N Tenzan was the Imperial Japanese Navy's standard carrier-borne torpedo bomber during the final years of World War II and the successor to the B5N "Kate"...

 "Jill" torpedo bombers. By this time, however, the shortage of carrier-qualified aircrew was such that they were ordered to operate from shore bases and Katsuragi never embarked her air group.

Armor, armament and sensors

Katsuragis waterline

Waterline

The term "waterline" generally refers to the line where the hull of a ship meets the water surface. It is also the name of a special marking, also known as the national Load Line or Plimsoll Line, to be positioned amidships, that indicates the draft of the ship and the legal limit to which a ship...

 armored belt

Belt armor

Belt armor is a layer of heavy metal armor plated on to or within outer hulls of warships, typically on battleships, battlecruisers and cruisers, and on aircraft carriers converted from those types of ships....

 was made from New Vickers Non-Cemented armor 25 millimetre thick. Her deck armor

Deck (ship)

A deck is a permanent covering over a compartment or a hull of a ship. On a boat or ship, the primary deck is the horizontal structure which forms the 'roof' for the hull, which both strengthens the hull and serves as the primary working surface...

 above the magazine

Magazine (artillery)

Magazine is the name for an item or place within which ammunition is stored. It is taken from the Arabic word "makahazin" meaning "warehouse".-Ammunition storage areas:...

s that consisted of 56 mm (2.2 in) of CNC1 armor. The ship's machinery spaces and auxiliary machinery rooms had two layers of Ducol steel, each 25 mm thick, to protect them. Above engine and boiler rooms, the lower deck consisted of 25 mm of CNC2 armor. The deck over the rear auxiliary machinery space was 42 mm (1.7 in) of CNC2 armor while the lower platform deck over the forward auxiliary machinery space consisted of 56 mm of CNC2. The upper hangar deck served as the ship's strength deck and it consisted of five layers of Ducol steel, a total 115 mm (4.5 in) in thickness. Katsuragis aviation gasoline tanks were fore and aft of the auxiliary machinery spaces and were protected by 50 mm (2 in) of Ducol steel in two layers while the deck above them consisted of 25 mm of CNC2 armor. The sides, bottom and top of the steering gear compartment consisted of 56 mm of CNC1 armor.

The ship's primary armament consisted of a dozen 40-caliber

Caliber (artillery)

In artillery, caliber or calibredifference in British English and American English spelling is the internal diameter of a gun barrel, or by extension a relative measure of the length....

 12.7 cm Type 89

12.7 cm/40 Type 89 naval gun

The 12.7 cm/40 Type 89 naval gun was a Japanese anti-aircraft gun introduced before World War II. It was the Imperial Japanese Navy's standard heavy AA gun during the war.-External links:*...

 anti-aircraft

Anti-aircraft warfare

NATO defines air defence as "all measures designed to nullify or reduce the effectiveness of hostile air action." They include ground and air based weapon systems, associated sensor systems, command and control arrangements and passive measures. It may be to protect naval, ground and air forces...

 (AA) guns in twin mounts. Their sponson

Sponson

Sponsons are projections from the sides of a watercraft, for protection, stability, or the mounting of equipment such as armaments or lifeboats, etc...

s were positioned to allow them some measure of cross-deck fire. Katsuragi was also equipped with 22 triple 25 mm Type 96 and thirty single AA gun mounts, most on sponsons along the sides of the hull. These guns were supplemented by six 28-round AA rocket launchers. For defense against submarines, the carrier was fitted with six depth charge throwers and carried between six and ten depth charges for them.

Two Type 94 high-angle fire-control directors, one on each side of the ship, were fitted to control the Type 89 guns. Each director mounted a 4.5 metre rangefinder

Rangefinder

A rangefinder is a device that measures distance from the observer to a target, for the purposes of surveying, determining focus in photography, or accurately aiming a weapon. Some devices use active methods to measure ; others measure distance using trigonometry...

. Six Type 95 directors controlled the 25 mm guns and the 12 cm rocket launchers. Early warning was provided by two Type 2, Mark 2, Model 1 air search radar

Radar

Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

s. One of these was mounted on the top of the island while the other retracted into the port side of the flight deck, between the two elevators. In addition, Katsuragi had two smaller Type 3, Mark 1, Model 3 air search radars, one mounted on the tripod mast on the island and the other on the aft starboard retractable radio mast. She also had two radar detector

Radar detector

A radar detector is an electronic device used by motorists to detect if their speed is being monitored by police or law enforcement using a radar gun. Most radar detectors are used so the driver can reduce the car's speed before being ticketed for speeding...

s: a metric Type E-27 and a centimetric Model 3 system. The ship had a Type 93 sonar

Sonar

Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...

 and two Type 0 hydrophone

Hydrophone

A hydrophone is a microphone designed to be used underwater for recording or listening to underwater sound. Most hydrophones are based on a piezoelectric transducer that generates electricity when subjected to a pressure change...

s with which to search for submarines. Before the end of the war, a Type 2, Mark 2, Model 4 surface fire-control radar was installed. In addition, a Type 14 early warning radar

Early warning radar

An early warning radar is any radar system used primarily for the long-range detection of its targets, i.e., allowing defences to be alerted as early as possible before the intruder reaches its target, giving the defences the maximum time in which to operate...

, ordinarily land-based, was mounted for trials aboard ship.

Service

Katsuragis keel

Keel

In boats and ships, keel can refer to either of two parts: a structural element, or a hydrodynamic element. These parts overlap. As the laying down of the keel is the initial step in construction of a ship, in British and American shipbuilding traditions the construction is dated from this event...

 was laid down by the Kure Naval Arsenal

Kure Naval Arsenal

was one of four principal naval shipyards owned and operated by the Imperial Japanese Navy. -History:The Kure Naval District was established at Kure, Hiroshima in 1889, as the second of the naval districts responsible for the defense of the Japanese home islands along with the establishment of the...

 in Kure, Hiroshima

Kure, Hiroshima

is a city in Hiroshima prefecture, Japan.As of October 1, 2010, the city has an estimated population of 240,820 and a population density of 681 persons per km². The total area is 353.74 km².- History :...

, on 8 December 1942. She was launched

Ship naming and launching

The ceremonies involved in naming and launching naval ships are based in traditions thousands of years old.-Methods of launch:There are three principal methods of conveying a new ship from building site to water, only two of which are called "launching." The oldest, most familiar, and most widely...

 on 19 January 1944 and completed on 15 October 1944. The ship was transferred among a number of ports on the Inland Sea until she arrived in Kure on 15 February 1945 and she was ordered to be camouflaged. Her intended air group, Air Group 601, was committed to the Battle of Iwo Jima

Battle of Iwo Jima

The Battle of Iwo Jima , or Operation Detachment, was a major battle in which the United States fought for and captured the island of Iwo Jima from the Empire of Japan. The U.S...

 about that same time. On 19 March, the ship was attacked by aircraft from Task Force 58 and lightly damaged by several rocket hits; one man was killed and three wounded in the attack. Five days later, the ship was permanently moored at an island in Kure harbor and extensively camouflaged. Aircraft from Task Force 38 attacked the ship on 24 July, but she was only hit once. A 500 pounds (226.8 kg) bomb struck one of the ship's anti-aircraft mounts on the port side. Thirteen men were killed and five wounded, but the bomb did little other damage. A second raid on 28 July did far more damage to the ship as a 2000 pounds (907.2 kg) bomb penetrated the flight deck and detonated in the upper hangar, between the elevators. The explosion blew out a 20 feet (6.1 m) section of the port hangar wall and the walls of the upper hangar deck were bulged and perforated multiple times. The flight deck between the elevators was bulged up and buckled; one section of the flight deck out was blown out and flung over to starboard to land across the funnels. Only 13 men were killed and another 12 men were wounded during the attack.

Katsuragi survived the war without sustaining any further damage, and was designated as a Special Transfer Ship on 2 October and then assigned to repatriation duty on 13 October after the necessary repairs were made. Her crew at this time consisted only of 12 officers, 1 warrant officer

Warrant Officer

A warrant officer is an officer in a military organization who is designated an officer by a warrant, as distinguished from a commissioned officer who is designated an officer by a commission, or from non-commissioned officer who is designated an officer by virtue of seniority.The rank was first...

, and 40 petty officer

Petty Officer

A petty officer is a non-commissioned officer in many navies and is given the NATO rank denotion OR-6. They are equal in rank to sergeant, British Army and Royal Air Force. A Petty Officer is superior in rank to Leading Rate and subordinate to Chief Petty Officer, in the case of the British Armed...

s and men. The damage from the July attack was only repaired enough to allow the hangar deck to house some 5,000 returning soldiers and civilians and the ship began her first voyage outside Japanese waters on 19 December. Upon her return, further repairs were necessary to make her rain-tight. These were completed by 15 January 1946 and she made a number of trips in early 1946 to bring back Japanese nationals before being placed on standby in April. Katsuragi was stricken from the Navy List

Navy List

A Navy List or Naval Register is an official list of naval officers, their ranks and seniority, the ships which they command or to which they are appointed, etc., that is published by the government or naval authorities of a country....

 on 15 November and transferred to the Home Ministry for disposal five days later. Scrapping of the ship began on 22 December 1946 at the Hitachi Zosen facility in Osaka

Osaka

is a city in the Kansai region of Japan's main island of Honshu, a designated city under the Local Autonomy Law, the capital city of Osaka Prefecture and also the biggest part of Keihanshin area, which is represented by three major cities of Japan, Kyoto, Osaka and Kobe...

-Sakurajima and was completed on 30 November 1947.

Cultural References

In the Japanese anime

Anime

is the Japanese abbreviated pronunciation of "animation". The definition sometimes changes depending on the context. In English-speaking countries, the term most commonly refers to Japanese animated cartoons....

 Neon Genesis Evangelion

Neon Genesis Evangelion

, commonly referred to as Evangelion, is a commercially and critically successful Japanese anime series that began airing in October 1995. The series was highly influential, and launched the Neon Genesis Evangelion franchise. It garnered several major animation awards...

, the last names of most primary characters are taken from warships. Misato Katsuragi

Misato Katsuragi

is a fictional character from the Neon Genesis Evangelion franchise created by Hideaki Anno. She is the operations director at Nerv, initially with the rank of captain; she is later promoted to major. In Rebuild of Evangelion Misato's rank is lieutenant colonel...

is named for this vessel.